Intermittent inductive a. c. train-control system



Patented Mar. 26, 1929.

UNITED STATES rA'rsnr OFFICE.

CHARLES F. ES'IW'ICK, O]? ROCHESTER, NEW YORK, ASFFJIGNOR T0 GENERAL RAILWAY SIGNAL COMPANY, 013 ROCHESTER, NEW YORK.

INTERMITTENT INDUCTIVE A. C. TRdlll-KTOITTEOL SYSTEM.

Application filed March 12, 1927.

This in vention relates in general to railway train control systems, and has more particular reference to an automatic intermittent inductive alternating; current type of system.

It is usual in systems ot the character in question to control. a brake applying or train movement restricting device in accordance with trallic conditions ahead, by means 01? coactiug trackway inductors and a car-carried receiver arranged to pass over the inductor in inductive relation thereto. In such sys tems it is quite essential that the operation oi: the inductors and receivers be certain and uniform.

With the above and other considerations in mind, it is proposed, in accordance with this invention, to provide an improved type of inductor and receiver. More specifically, the inductors comprise spaced parallel magnetic cores with coils thereon connected up through a tuned circuit to be controlled in accordance with traflic conditions ahead, while the receivers comprise two opposed spaced parallel cores with an obliquely arranged core thercbetwcen, the cores being supplied with primaryand secondary windings, properly placed, for accontlplishing the desired results.

Further objects, purposes, and characteris tic features of the invention will appear as,

the description progresses, reference being had to the accompanying drawings, showing solely by way of illustration, two physical embodiments of the invention, in connect-ion with a simplified train control system. In the drawings i Fi 1 is a schematic representation of apparatus in accordance with this invention;

2 is a schematic showing of a portion of the apparatus in a different operative position from that of Fig. 1; and

Fig. 3 shows a slightly modified arrangement of parts of the system.

Referring to the drawings, and more particularly to 1, a stretch oi? trackway is shown constituted by track rails 1, separated into signalling blocks by insulating; joints 2. Each block has a usual track relay 3 at its entrance end and a track battery 4!: at its exit end. Signals 5, of the semaphore type, have been shown at the entrance end to each block, but these could obviously be of any other desired type.

serial No. 174,359.

The ti.'acl-;way inductor of this invention is positioned adjacent the entrance end of each block and comprises two parallel spaced cores (5, preferably of laminated material, supplied with windings 7 connected in series with each other, with a condenser 8, and a contact finger 9 and trout contact oi? the adjacent track re lay, the constants oi the circuit being such as to give the maximum clearing elifcct, that is, the maximum holding up cttect on a car-carried mainrelay, when inductively influencing a car-carried receiver.

, The various operatic circuits and devices for controlling the wayside signals, can be of any usual or desired type, and are well understood by those skilled in this particu lar art.

I'l.he apparatus carried by the car, represented diagrammatically by wheels and axles 10, includes the receiver of this invention, comprising spaced parallel cores 11, with a pivoted, obliquely positioned, core 12 therebetweon, all of which are prcifcrably made of laminated n'laterial to cut down losses. On opposite ends oi the core 12 are primary windings P and P connected in series with each other, with a tuning condenser 13, and a source of alternating current 14:. The current supplied by the source 14: is preferably Of a 'lrequen cy higher than the usual commercial ttrcmiencics, an d is of the order of 360 cycles per second, for example.

On oppositc ends of the parallel spaced cores 11, are secondary windings S and S", connected in series with each other, with a tuning); condenser 15, and a main control relay MR.

As is usual in systems of this character, a meansfEPl is provided for controlling the car brakes or imposing any desired speed restricting influences on the car, and in the case represent-ed, an clectro-magnetic device which normally energized through a circuit including a battery 16 or its equivalent, and contact linger l7 and. front contact otlirclay ME. The bralre device EPV, when ee-energ iz operates to exert a train movement restricting influence oi the desired charactor.

The receiver is positioned on the car so as to pass directly over the traclcway inductors, in the manner indicated in Fig. 2, at the entrance to each block, there being a short vertical air gap between the inductor and receiver throughwhich the receiver is inductively inscribe'dbelow. V

As an alernatlve arrangement, the 1nducfluenccd under; certain conditions, to be dctor core can be placed to parallel the track rails 1, withthe receiver correspondingly changed in position, as shown in Fig. 3, with which arrangement the effect ofthe inductor on thereceiver, is felt sooner before, and con tinned longer atter, passage or the receiver directly over the inductor, than with the first arrangement (Figs. 1 and 2),

Each trackway inductor, 'as shown, is controlled by a track relay to placethewindings 7 in either open or closed circuit condition. When. the windings 7 are in a closed circuit their choking effect is so great, that the cores 1 lay 3' is de-energized, the inductor isin active produces condition, while when energized, it is inactive." lvhlle the arrangement shown in the drawing permits of only two controls for the inductor, namely, clear and danger, it is obvious that a usual line relay, having a front contactincluded in the circuit of the windings"7,ancbco'ntrolled in accordance with traflic conditions iirthe second block in advance of the inductor in'question, could be used, for the inductor to be controlled to be active under both caution and danger conditions, and inactive under clear conditions. an example of this type of control is shown in the p'a'tent'to W. K. Howe,-1,60l,098 of October 19, 1926', to which attention isdirected. V

Under normal; conditions, the current suppliedto the primary windings P and P oppositely directed, opposing, fluxes in the corell, in the manner indicated "by the arrows in Fig. 1, and these fluxes follow the magnetic circuit having the least reluctance,which results in the flux produced by winding P passing through secondary windmg S n the direction indicated by the arrow (Fig. 1') while that produced by primary winding 1, passes through secondary coil winding-S in the direction indicated by the arrow (F 1). The win-dings S and S so connected as to have their induced voltages I cumulative, whereby to send induced currentthrough-the winding of the main relay MRand thus maintain the brake device EPV in energized condition.

VVhen' an inductor is in inactive condition, that 1s, closed cn'cuited, such as occurs under. 7 clear-conditions, and 1s passed over by a receiver, the flux distribution in the various receiver cores 11 and 12 is not materially changed, since thechoking effect of the wind- "ings 7 effectively prevents passage of flux therethrough, and as a result the relay MR remains energized and no restricting influonce is incurred.

Assuming, how ver, that the train in question is passing into a caution or danger block, under which conditions the windings 7 of the inductor at the entrance to such block are open circuitcd so that the inductor is active, a rc-distribution of magnetic flux in the receiver takes place. The inductor cores 6 span across the ends of the receiver cores 12 (Fig. 2) and provide a second and alternative, magnetic path for the flux produced by each primary winding P and l, in a direction as indicated by arrows 18 in Fig. 2. The air gap between the inductor and receiver, and the proportions of the various parts, and the adjustment cll'ectcd by rocking core 12 on its pivot, are such as to make the reluctances of the two alternative magnetic paths for flow of the flux produced by each primary winding, substantially equal. It will be noted that the existence of two paths in question, for each primary flux, tends alternative paths in question be exactly equal,

and the fluxes in phase no flux will pass through the secondary windings whereas, if they are somewhat unequal, or somewhat out of phase, a small resultant amount of flux will pass through the secondary windings in one direction or the other. In any event, however, on the passage of a receiver over an active inductor, the voltages induced in the secondary windings S and S will be reduced to zero or will be so substantially reduced, as to cause de-cncrgization of main relay MR, with a resulting de-cnergization of EPV and the imposition of a train movement restrictinginfluence.

In the drawing, no usual acknowledging and reset devices have been shown in connection with the brake applying apparatus, but such devices obviously could be utilized if desired, in any usual or conventional way, such as is illustrated, and described, for cxample, in the Howe Patent 1,604,098, referred to above. With such devices used in connection with the system shown, by proper operation of the acknowledging device, the train movement restricting influences can be prevented even though relay MR be de-cnergized, while it such restricting influence be incurred, operation of the reset device will restore the various parts to normal position.

It is important to note in connection with the receiver described and illustrated, that the two primary windings P and P cause fluxes to flow in opposite and opposed directions, and furthermore, that the secondary windings have their induced voltages changed by a tendency for flux to reverse its direction of flow therethrough, and that there has not been provided, in said receiver, as is usual practice, a separate bucking winding which has, at times, a voltage induced therein which is opposed to that in the secondary windings,

and connected in series therewith. In the use of a bucking winding, should such winding be shunted out by a short circuit or the like, the system would operate to give a false clear indication whereas, any shunting out of the secondary windingsin the present instance would cause only a false danger indication, and so that all errors are on the side of safety.

The above rather s 'iecilic description of one form of the invention, is given solely by wayoii example, and not intended, in any manner whatsoever, in a limiting sense. Ob.- viously, the invention can assume many dil terent physical terms, and is susceptible of numerous ll'lOCllllCLtlODS, and it is intended to include, in this application, all such forms and modifications as come within the scope of the appended claims.

Having described my invention, I now claim 1. In a train control system, a car-carried receiver, comprising, two parallel, spaced cores, a secondary winding on each core, a core obliquely positioned between the parallel cores, primary windingsplaced on the oblique core to be nonsymmetrical relative to said parallel cores, means for energizing the primary windings with alternating current, and a break applying device controlled by the secondary windings.

2. In a train control system, a car-carried receiver, comprising, two parallel, spaced cores, a secondary winding on each core, an obliquely positioned core between the parallel cores, primary windings on the oblique core ncnsynnnetrical relative to said parallel cores, means for energizing the primary windings with alternating current, a brake applying device controlled by the secondary windmgs, and a cooperating trackway inductor, including spaced parallel inductor cores positioned at right angles to the parallel cores of the receiver.

3. In a train control system, a car-carried receiver, con'iprising, two pa 'allel, spaced cores, a secondary winding on each core, a core nonsymmetricaly positioned between the paralel cores, primary windings on the last mentioned. core positioned nonsyi'nmetrically relative to said parallel cores, means for energizing the primary windings with alternating current, a brake applying device 0011- trolled by the secondary windings, and a cooperating trackway inductor, including spaced parallel inductor cores positioned at right angles to the receiver parallel cores, and in a plane substantially parallel with that of the receiver cores.

t. In a train control system, a carcarried receiver, comprising, two parallel, spaced cores, a secondary winding on each. core at non-opposed ends thereof, a core obliquely positioned between the parallel cores, primary windings on the oblique core at the respective ends thereof, means tor energizing the primary windings with alternatingcurrcnt, and a brake applying device controlled by the secomlary windings.

5. In a train control system, a car-carried receiver, comprising, two parallel, spaced cores, a secondary winding on each core at non-opposed ends thereof, a core obliquely positioned between, and inductively related to, the paralel cores, primary windings on the oblique core, means for energizing the primary windings in series with alternating current, and a brake applying device controlled by induced current flowing in, the secondary windings.

G. In a train control. system, a car-carried receiver, con'iprising, two parallehspaced cores, a secondary winding on each core at non-opposed ends thereof, a core obliquely positioned between the parallel cores, primary windings on the oblique core at the respective ends thereof, and inductively related to the secondary windings, means for energizing the primary windings in series with alternating current, and a train restrict ing device controlled by induced current flowing in the secondary windings.

7. In a train control system, a car-carried receiver, comprising, two parallel, spaced cores, a winding on each core at non-opposed ends thereof, a core obliquely positioned be tween the parallel cores, windings on the oblique core, at the respective ends thereof, and inductively related to the first said windings, means for energizing one set of windings with alternating current, a brake applying device controlled by the other set o'l windings, the el'iergized windings being arranged to produce fluxes flowing toward each other, and the other secondary windings being arranged to causefluxes to flow in opposite directions.

8. In a train control system, a car-carried receiver, con'lprising, two parallel, spaced cores, a secondary winding on each core at non-opposed ends, thereof, a core obliquely positioned between and in inductive relation to, the parallel cores, primary windings on the oblique core at the respective ends thereof, means for energizing the primary windings in series with alternating current, a train restricting device controlled by induced current flowing in the secondary windings, the primary windings being arranged to produce fluxes flowing toward each other, and the secondary windings being arranged to cause fluxes to flow therethrough in oppositedt rections.

9. In a train control. system, a ear-carried receiver, comprising, two parallel, spaced cores, a secondary winding on each core, an

' adjustable, obliquely positioned core between the parallelcores, primary windings onthe oblique core, means for energizing the primarywindings with alternating current, and a train restricting devlce'controlled by the secondary windings,

for energizing the primary windings with V alternating current,and a train restricting device controlled by the secondary windlngs. j 11. In atrain control system, a'car-carried receiver, comprising, two parallel, spaced cores, a secondary winding on each; core, an

obliquely positioned core'betwe'en the parallel cores, primary windings on the oblique core positioned n'onsymmetrically relative to said parallel cores, means for-energizing the primary windlngs with alternating current, a

brake applying device controlled by the secondary windings, and a cooperating tracluvay inductor, including spaced parallel inductor cores positioned at right angles to said parallel-cores, for respectively spanning across the ends of the said parallel cores.

12. In a train control system, a car-carried receiver, comprising, two parallel, spaced cores, a secondary winding on each core, an obliquely positioned core between the parallel cores, primary windings on the oblique core positioned nonsynnnetrically relative to said parallel cores, means for energizing the primary windings with alternating current, a b ake applying device controlled by the seconary windings, and a cooperating trackway inductor, including spaced parallel inductor cores positioned at right angles to said parallel cores, for respectively and simultaneously spanning across the ends of the said parallel cores.

In testimony whereof I afiix my si mature.

CHAR-LES F. EST ICK. 

